St. Mary's Duluth Clinic (SMDC) Pacemaker Magnetic Resonance Imaging (MRI) Study

SMDC Pacemaker-MRI Cohort Study

The purpose of this study is to monitor and follow non-pacemaker dependent patients with implanted permanent pacemakers, who undergo medically required Magnetic Resonance Imaging (MRI) scans.

Patients with pacemakers are currently excluded from obtaining MRI scans. MRI scanning is now the imaging of choice for a number of neurological, vascular, or musculoskeletal conditions.

Data suggests that patients with pacemakers, when properly monitored, can safely undergo MRI scanning, though the largest published study to date consists of 54 patients, and no long term follow-up has been published.

Though MRI cardiac scanning has been demonstrated to produce local tissue heating at the pacemaker lead tip, the long term effect of tissue heating on lead stability is unclear.

This study will evaluate patients with permanent pacemakers undergoing medically indicated MRI scanning.

Patients will be followed for one year at 3, 6, and 12 months. Data collected will evaluate change in pacing thresholds over time as well as cardiac troponin I, creatinine kinase MB function, and myoglobin levels within the first 12 hours following the scans, side effects, symptoms, the need to make pacemaker program changes, and possible artifacts created by the pacemaker on the MRI scan.

Inclusion Criteria:

• Permanent pacemaker or ICD implanted for at least 6 weeks
• Referred for medically indicated MRI
• Age greater or equal to 18 years old

Exclusion Criteria:

• ICD market released before 2001 including GDT Ventak-AV, GDT MINI-II, GDT MINI-IV, GDT MINI-III, GDT Prizm-2 MDT GEM-I series
• Epicardial coronary sinus lead or subcutaneous array
• Unable to program all leads to bipolar configuration
• Pacemaker Dependent
• Device has reached elective replacement or end of life
• Other usual contraindications to MRI scanning
• The use of inotropic pharmacological agents, such as dobutamine, during the MRI